1. Field of the Invention
The present invention relates to a method of manufacture a golf head and more particularly to a method of manufacturing a face with different thickness distribution.
2. Description of the Related Art
In the prior art, a cup face having a different thickness distribution is usually make made from a metal rod by forging, and the pressure of the forging must be higher than 400 tons. The method will lose about 50% of the raw material. As a result the crystals of the metal will change and the strength of the material is reduced when the temperature is higher than 800° C., so the manufacture temperature must be controlled under 800° C. if the manufacturer wants to use β titanium material to make the face. But, it is difficult to make a metal rod into a face with the thickness between 1.5 to 4 mm by forging under such a low manufacture temperature. Avoiding damage to the face will be difficult to control. As is known, there is a face in a cup shape. It will be more difficult to make a rod into a cup face with the thickness between 1.5 to 4 mm by forging under the low manufacture temperature.